1. Field of the Invention
The invention relates to a rope guide arrangement for guiding a leader strip of a material web through a processing device having a machine direction and a transverse machine direction. The arrangement includes at least two ropes arranged offset relative to one another in a first plane defined by the machine direction and the transverse machine direction.
2. Discussion of Background Information
Within the course of its manufacture, a paper web must be guided through several processing devices, for example, a press section, a drying section, a calender, a coating device, a size press or the like. A rope guide arrangement is often used for this purpose, which forms a rope nip at the beginning of a processing device. Ropes from different directions are brought together in this rope nip. A strip that has been cut with a width of approximately 20-30 cm at the edge of the paper web is guided into the rope nip formed by ropes converging to hold the leader strip in a clamping manner and to guide the leader strip along the web travel path running through the processing device. When the leader strip has been guided through the processing device and a tensile force can be exerted on the leader strip after the processing device in the web travel direction, the paper web will be cut to width so that it then runs through the processing device in its full width.
The direction in which the material web runs through the processing device is usually called the “machine direction.” A direction perpendicular thereto is called the “transverse (crosswise) machine direction.”
A rope guide arrangement of the type mentioned at the outset is known, e.g., from DE 696 08 658 T2. According to this arrangement, two ropes are arranged in a plane stretching through the machine direction and the transverse machine direction. Thus, the ropes run parallel to a plane in which the material web later moves.
Usually, two or three ropes are used. In the case of two ropes, the inside rope, i.e., the rope facing or adjacent the processing device lies, e.g., below the leader strip, and the other rope lies above the leader strip. In the case of three ropes, the two outer ropes lie, e.g., below the leader strip and the center rope lies above the leader strip. However, the arrangement can also be reversed. More than three ropes can also be used.
Although the threading operation for a material web has by now become a standard operation, the leader strip often tears, even if the threading process is carried out carefully. This situation can also occur after the leader strip has left the rope guide arrangement, results in a repetition of the threading process and an associated a loss of time. This lost time is not available for the actual production.